Au@Ag@Pt Trimetallic Nanoparticle-Enhanced Dual-Mode Lateral Flow Immunochromatographic Assay for Ultrasensitive and Rapid Detection of Acetamiprid in Plant-Based Foods

Acetamiprid (ACE) is a widely used neonicotinoid insecticide with potential health risks due to its persistence in the environment and bioaccumulation in plant-based foods. In this study, an improved dual-mode lateral flow immunochromatography assay (DMLFIA) was established for the sensitive detection of ACE residues in plant-based foods using Au@Ag@Pt NPs as dual-function signal probes. In the colorimetric mode (Mode 1), with the inhibition rate as the vertical coordinate and the ACE concentrations as the horizontal coordinate, the linear detection range of the colorimetric mode was 0.1–3000 μg/L with the detection limit of 0.08 μg/L. In the photothermal mode (Mode 2), the temperature values obtained via smartphones integrated thermal imager showed a linear relationship with 0.1–3000 μg/L of ACE, and the detection limit is 0.1 μg/L. The cross-reactivity rate of the developed DMLFIA with other structural analogs and functional substances was less than 0.39%. The recovery rate of the developed DMLFIA used in spiked plant-based foods was 81.1–99.4%, with relative standard deviations (RSD) of 1.3–10.7%. The detection results of this constructed DMLFIA showed good consistency with those obtained by HPLC and ELISA. The constructed DMLFIA provides a selective, sensitive and rapid detection tool for ACE in different scenarios in plant-based foods.